Refrigerating apparatus



Aug. 19, 1941. F. s TH REERIGERATING APPARATUS 4 Sheets-Sheet 2 iled se t 28, 19:57

INVEN OR.

ATTORNEYS 4 Sheets-Sheet 3 /50 b? I VENTOR 4% ATTORNEYS Aug. 19, 1941. H. F. sMT- REFRIGERATING APPARATUS Filed Sept. 28, 1937 1941- H. F. sMTH 2,253,252

REFRIGERATING APPARATUS I I I Filed Sept. 28. 1937 4 Sheets-Sheet 4 r INVNTOR. BY y ATTORNEYS Patented Aug. 19, 1941 REFRIGERA'I'ING APPARATUS Harry F. Smith, Dayton, Ohio, asslnor to General Motors Corporation, Dayton, Ohio, a corporation ot Delaware Application September 28, 1937, Serial No. 166.134

8 Claims.

This invention relates to reirigerating apparatus and more particularly to means for opening refrigerator doors, holding the doors open and holding the doors closed, and also to means for opening and holding open other doors.

It is often desired to open refrigerator doors when one or both hands are filled with articles to be placed in the refrigerator. Some manufacturers have attempted to solve this problem by providing foot pedal operated latches, but such latches are relatlvely diflicult to operate and the relatively greatdistance between the pedal and the latch makes the problem of cabinet Construction rather di-filcult. Various types of mechanical push type latches have been designed, but these do not operate sufflciently easy to permit the easy opening of the door which is required when the hands and arms are loaded with articles to be placed in the cabinet.

It is an object of my invention to provide a form of latch means in which the door is readily opened with only a very slight pressure, and which is readily accommodated in the walls of the door and the cabinet.

It is another object of my invention to provide a latch means without moving parts.

It is another object of my invention to provide a simple means for holding a door closed and a simple means for opening the door which is operated by manually controlled electrical power.

It is a further object of my invention to provide a door with means for holding the door tightly closed, and means for holding open the door, and a means for closing the door, all of which may be readily controlled by a manual electrical. switch It is another object of my invention to provide a means for controlling the attraction between a permanent magnet and an electromagnet.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a front view of a refrigerator embodying my invention shown with the door open;

Fig. 2 is a sectional view taken along the line 2--2 of Fig. 1;

Fig. 3 is a sectional view taken along the line 3--3 of Fig. 2;

Fig. 4 is a sectional View taken along the line 4-4 of Fi 1;

Fig. 5 is a sectional view taken along the line 5--5 of Fig. 4;

Fig. 6 is a wiring diagram showing the wiring of the electrical system for holding the door closed, pushing the door open and holding the door open;

Fig. 7 is a sectional view taken through the cabinet at one of its hinges;

Fig. 8 is a wiring diagram of a modified form of the invention; and

Fig. 9 is a sectional view through a different type of a refrigerator cabinet showing a modified form oi' the invention.

Briefly, in Figs. i to 7, I have provided a refrigerator with an electromagnet located in the door' and a permanent magnet in the door jamb. When the electromagnet is deenergized, the permanent magnet will attract its core to hold the door closed. The hinge of the door is provided with a light spring for urging the door to closing' position and within the cabinet adjacent the hinge of the door, an electromagnet is provided for holding open the door. A push button is provided at the side of the door and a foot pedal operated switch is provided at the bottom of the cabinet, either of which will energize both of the electromagnets. The energization of the electromagnet in the door will cause the electromagnet to assume like poles with respect to the permanent'magnet, thereby causing a powerful repulsation between the two magnets to push the door open.

The second electromagnet is also energized either by the foot pedal or the push button as desired in order to hold the door open. When the push button and the foot pedal are in released position, both electromagnets are deenergized and the door is moved towards closed position by the light spring and held tightly shut by the action oi' the soft iron core of the electromagnet by the permanent magnet.

Fig. 8 shows a modification in which the electromagnets are used both in the door and in the door jamb. Fig. 9 shows a modification in which the permanent magnet is provided in the door and an electromagnet is provided in the door jamb.

Referring now to the drawings, and more particularly to Fig. 1, there is shown a refrigerator 20 provided with an insulated food compartment 22 and a machine compartment 24 below the food compartment. The machine compartment is provided with a sealedunitzfi containing an electric motor and a compressor directly connected to the electric motor for compressing refrigerant and for forwarding the compressed refrigerant to a condenser where the compressed refrigerant is liquened, thence forwarded to a cooling unit 20 which is located in the food compartment 22 for cooling the air and the contents of the food compartment. The refrigerant evaporates within the cooling unit !I and is returned to the compressor. The compressor is supplied with electric energy from a power supply through an electric supply conduit 30 and a conductor 32. Also connected to the electrical supply conduit 30 is a transformer and an alternating to direct current converter 04.

The food compartment !2 is provided with an insulated cabinet door which is pivotally momted upon a pair of hinges. one of which is shown in Fig. 'I and designated by the reference character 00. The portion of the cabinet surrounding the door when in closed position is called the door jamb.

Eeretofore. it has been customary to provide a mechanical latch upon the face of the door or within the door and a keeper upon or within the door jamb. ly, some manufacturers have provided a foot pedal at the bottom of the door which was connected by rods to a trigger within the keeper which was capable of pushing the latch out of engagement with the keeper. At other times, some form of handle or tripping mechanism was provided either on the face of the door or upon the face of the door jamb. With any of these types of latches, there was always some difliculty in opening the door when the arms and hands were filled with articles intended for the food compartment. Some have proposed electromagnetic operated latches, but such latches are rather complicated, since the usual mechanical latch mechanism must be provided in addition to the electromagnetic means for operating the latch mechanism.

In my invention. I do away with the mechanical latch mechanism and merely use a set of magnets for holding the door in closed position and include at least one electromagnet to create a polarlty like that of the other magnet in order to cause a repulsion between the magnets for pushing open the door. This repulsion may be made as powerful as desired and this will govem the force. and. tberefore. the distance the door is swum open.

It is. of course, desirable to employ a permanent magnet as the magnet with which to hold the door in closed position, because no current is then needed to hold the door closed. However, in the past. it has been found impossible to cause sufiicient repulsion between a permanent magnet and an electromagnet to permit them to be separated without an undue force being required to aid in the separation. I have found that this is overcome by fastening a soft iron member to a permanent magnet and locating this soft iron member so that it has a face which comes substantially into contact with the face of the electromagnet; and I have further found that a very powerful repulsive force between the electromagnet and the soft iron piece attached to the permanent magnet can be obtained by a relatively small amount of current passing through the electromagnet. In this way. it is possible to employ a permanent magnet for holding the door shut and to employ an electromagnet merely for pushing open the door. Therefore, only a small expenditure of electric energy is required by the door over extremely short periods of time.

In Flgs. 2, 4 and inclusive, there is shown an electromagnet 40 of the U-shaped type. which is mounted in the cavity 42 in the door frame 44.

This electromagnet 40 is fastened by a long screw 46 to a plate 48 which is fastened to the door frame 44 and extends over the cavity 42. This plate 40 is provided with apertures through which the core of the electromagnet may extend. The protruding faces of the electromagnet may be ground so as to provide a smooth face. This plate 40 is securely fastened to the door frame 44 and thereby flrmly supports the electromagnet 40.

A soft iron piece, mentioned before, is 'designated by the reference character 50 and has a face 52 which extends into close contact with the faces of the electromagnet 40. These soft iron pieces 50 are flrmly fastened to the faces of the U-shaped permanent magnet 54 by a thin plate 50 and by a bolt which extends through the thin plate 58 and through a heavy wedge II which is lodged between the pole portions of the permanent magnet 04. In this way, the soft iron pieces 00 are tightly .clamped to the faces of the pole portions of the permanent magnet 04,

The permanent magnet 54 is located within a cavity I! provided for it within the insulation 04 and the door :amb or frame 05. The front edge 68 of the inner liner 10 which lines the food compartment 22 is separated from. and insulated from the permanent magnet by a suitable gasket member 12. The soft iron pieces 50 are silver soldered or otherwise fastened to a brass plate 14 which is fastened to the door Jamb frame by brass screws 18. This plate 14 is provided with Slots which receive the brass screws 'IS so that the location of the soft iron pieces and the permanent magnet may be adjusted. The cavity in the wall of the cabinet adjacent the door Jamb is covered by a door molding 10 which is provided with apertures through which the soft iron pieces 50 extend from the faces of the permanent magnet 54.

The electromagnet 40 as shown in Fig. 6 is connected to an electrical circuit which extends from the alternating to direct current converter by the electrical conductors and 92 which extend from the converter 34. From the conductor 02, another conductor 94 extends to a push button 96. Another conductor 08 extends to a foot pedal operated switch means !02 which is operated by a foot pedal I04. A conductor I is connected from the foot pedal switch |02 and connects to another conductor !00 which extends to the electromagnet 40. The push button 00 is also connected by a conductor |l0 through conductor l00 and the conductor !08 to the electromagnet 40. The electromagnet 40 is also connected by a conductor I |2 to the conductor 00. The push button 95 is preferably located upon the face of the door iamb adiacent the edge of the door so that it may be conveniently pushed immediately before opening the door. The foot pedal |04 and switch l02 is located at the bottom of the cabinet beneath the machine compartment 24. In order to connect the push button 96 and foot pedal |02 with the electromagnet, I have provided a set of spring contacts III and ll! in the conductor I08 for supplying energy to the electromagnet 40, and another set of spring contents |20 and !22 in the conductor ll! for the same purpose. However, any other srtdof suitable connection may be used if des e When either the push button or the foot pedal switch is closed, current flows from the converter through the electromagnet, thereby exciting the magnet to create poles like the poles of the permanent magnet 64. This causes a repulsion between the 'electromagnet and thfesoft iron pieces 66 which are fastened to the poles of the permanent magnet sufiiciently powerful to push the door open. With'merely this much oi' the apparatus employed, it -is undesirable to use a closing spring and the door may be easily' opened by either the push button or the foot pedal switch or both, and it will remain open until it is pushed shut. No force is required to hold the door open and only the lightest kind of push is required to c1ose.the door, because as soon as the face of the electromagnet and the face of the soft iron pieces are within several inches of each other, the permanent magnet will attract the electromagnet and pul] the door shut. This attraction, of course, increases as the faces become closer 'together and the door is held shut so tightly in this manner by its magnetic attraction upon the core of the electromagnet that it is very diihcult to open the door without proper energizaticn of the electromagnet.

However, in addition to this simple arrangement. I have connected a second electromagnet m to the conductors 90 and !06 so that this electromagnet is also energized whenever the push button 96 or the footpedal I 04 is moved to switch closing position. When this electromagnet !36 is employed. a closing spring [32 is also provided upon one or both hinges of the door. This closing spring should be very light, so that it may be easily overcome by the door opening push provided when the electromagnet 40 is energized. Only a light return spring is required to shut the door because it is not required to supply the force necessary to latch the door, because the latching is accomplished by the attraction of the permanent magnet for the core of the electromagnet, and this attraction pulls the door shut tight and holds it there.

The electromagnet m is lodged within a cavity |34 provided in the insulation and the door jamb frame in the cabinet. An armature |36 is provided tobe attracted by the electromagnet. This armature comprises a lever pivoted upon a pin !38 having a projection !40 at its opposite end which is in contact with a spring retainer |42 provided at one end of the compression type coil spring I44. Theopposite end of this spring,

|44 is provided with another spring retainer i46 which carries a pin i4'I for engaging a notch !50 provided in the door hinge. When the'electromagnet !30 is energized, the armature !36 is attracted to cause it to turn in a counterclockwise direction about its pivot pin |36, causing its proiection !40 to compress the spring i44 and, thereby, provide a spring force tending to push the door open.

According to the wiring system shown in Fig. 6, the electromagnet 40 is energized simultaneously with the electromagnet 130 so that at the same time the holding open means is effective,

the door is released and given an opening pushby the repulsion between the electromagnet 40 and the permanent magnet 54. This push, togethe' with the force oi' the spring I44, pushes the door open sufilciently wide to obtain easy access to the food compartment. Both electromagnets remain energized as long as eitherthe foot pedal or the push button switches are held closed. Thus, the doors may be held open by keeping one of these switches closed, and articles can very conveniently be placed in the refrigerator at this time. After the articles have been placed in the refrigerator, the switch which is struction is employed, and anelectromagnet 2||I is provided in a cavity 2i2 in the insulation 2|4 and the door jamb frame 2|6 of a refrigerator' cabinet 2|8. This electromagnet is connected to a direct current converter, similar to the converter 34, under the control of a push button 220 located upon a wall of the cabinet. A rather unusual 'type door 222 is provided and has a permanent magnet 224 concealed therein which is fastened to a pair of soft iron pole pieces 226, each having one end silver soidered to a plate 226 fastened by wood screws 236 to the door frame.- The other end of each of the soft iron pole pieces extends in close contact with one of the pole pieces of the electromagnet 2|0 which project from the door jamb. i

As in the other modification,` the permanent magnet holds the door closed when the electromagnet -is deenergized. When the electromagnet is energized by pressing upon the push button, like poles as the permanent magnet are excited within it causing a repulsion between the two magnets, pushing the door open.- This set of magnets may be used with the electrical circuits shown in F'ig; 6, or, if desired, it may be used with an electrical circuit like that of Fig. 6 without the electromagnet !30.

In Fig. 8, a wiring diagram is shown of another form of my invention, in which two .electromagnets are employed instead of a permanent magnet and an electromagnet. In this form, the door is designated by the reference character 240, and is shown in dotted outlines, while the door jamb is similarly shown and designated by reference character 242. A direct current converter 244 provided with an alternating current supply through the conductors 246 supplies direct current at a low voltage through the conductors 248 and 250 to an electromagnet 262 located within the door jamb 242. This electromagnet 252 is constantly connected to theconverter through conductors 264 and 266.. A second electromagnet 256 is provided in the door and has its pole disposed in close contact with the poles projecting from the door jamb. This electromagnet 256 is supplied with electric energy through the conductors 260, 262 and 264 under the control of a push button switch 266.

The electromagnet 262, which is continuously energized, attracts the soft iron core of the electromagnet 258 in order to hold the doors in closed position. However, when the push button 266 is closed, the electromagnet 258 is also energized to excite like poles within the electromagnet 258 which causes a repulsion between the two electromagnets, pushing the door open. The direct current converter 244 may be connected in the electrioal system of a refrigerator in the same manner as is shown in the modification embodied in Fig. 1. It may also be used with a second electromagnet for holding open the door as is shown in Flgs. 6 and 7, and the foot pedal switch may be provided in parallel circuit relation with the push button I" in a manner similar to that shown in Fig. 6. where two` electromagnets are employed, it is not necessary to employ the soft iron pole pieces between the two magnets.

Thus, I have provided a means whereby a repulsion may be caused between a permanent magnet and an electromagnet, and I further have provided magnetlc means !or causing repulsion between the magnets to push the door open and I further provide means !or holding open the door when desired. All of these may be accomplished merely by closing an electrical switch, and only a relatively small current ot the low voltage is required, and where no return spring is provided and no holding open electromagnet is provided. the door may easily be returned manually with a very slight push. Thus, I have provided a very convenient means for solving the retrigerator latch problems.-

However, my invention is applicable to many other purposes. The broadest aspect of my invention, the means !or causing repulsion between an electromagnet and a permanent magnet, is capable of the widest kind of application in many diflerent flelds, and is not limited to its use upon doors.

While the form of embodiment of the present invention as herein disclosed constitutes a prererred form, it is to be understood that other forms might be adopted, all coming within th scope of the claims which follow. r

What is claimed is as follows:

Rei'rigerating apparatus including a cabinet incorporating a cabinet member and a door member, a cooling unit i'or cooling the interier of the cabinet. an electrically operated liqueiying means for supplying refrigerant medium to and for withdrawing the medium from the cooling unit, a magnet upon each of the members, one ot said magnets being an electromagnet, said magnets being positioned to attract each other when the electromagnet is deenergized and to repel each other when the electromagnet is energized, said electromagnet being connected to the electrical system of the electrically operated liquefying means for supplying electrical energy to the eectromagnet, and means for controlling the energization o! the electromagnet.

2. Refrigerating apparatus including a cabinet incorporating a cabinet member and a, door member, a cooling unit !or cooling the interier ot the cabinet, an electrically operated liquetying means !or supplying refrigerant medium to and for wlthdrawing the medium from. the cooling unit, a magnet upon each o! the members,

one of said magnets being an electromagnet,`

said magnets being positioned to attract each other when the electromagnet is deenergized and to repe each other when the electromagnet is energized, a converter connected to the electrical system oi the electrically operated liqueiying means for supplying direct current to the electnomagnet, and means !or controlling the energization oi' the electromagnet.

3. The combination including a door member and a door Jamb member tor the door member. each of said members being provided with a magnet, one ot said magnets being an electromagnet, and means tor energizing the electromagnet to create repulsion between it and the other magnet !or opening the door member.

4. The combination including a door member' and a door Jamb member i'or the door member, each ot said members being provided with a magnet, and electrical means for controlling repulsion and attraction between the magnets !or pushing the door member open and !or holding the door memberclosed.

5. The combination including a door member and a door jamb member !or the door member, each of said members being provided with a magnet, means !or causing the magnets to assume unlike poles tor holding the door closed. and electrical means tor causing the magnets to assume like poles for pushing the door member open.

6. The combination of a door member and a door jamb member !or the door member, each of said members being provided with a member of magnetic material, the first oi' said members of magnetic material being a magnet, the second of said members of magnetic material being located adjacent the i'ace of the magnet when the door member is closed to enable the magnet to attract the second member of magnetic material !or holding the door member closed, and electrical means tor exciting a polarity in the second member of magnetic material like that of the magnet i'or causing a repulsion between the magnets for pushing the door member open.

7. The combination of a door member and a door Jamb member for the door member, one of said members being provided with a permanent magnet having soft iron pole i'aces, the other ot said members being provided with an electromagnet having its pole faces adiacent the pole faces of the permanent magnet when the door member is closed, said electromagnet having its poles arranged to produce when energized a polarity like that or the permanent magnet to cause a repulsion between the magnets to push open the door member.

8. The combination of a door member, and a door jamb member i'or the door member, each of said members being provided with electromagnets having adjacent pole Iaces when the door member is closed, said electromagnets, when energized, being arranged to provide a like pola-ity, and means for simultaneously energizing said electromagnets.

HARRY F. SMITH. 

